Answer:
t = 2.02 secs
Explanation:
Given the following data;
Height = 20m
We know that acceleration due to gravity, g = 9.8m/s²
To find the time, we would use the formula for maximum height;
H = ½gt²
Substituting into the equation, we have;
20 = ½*9.8t²
20 = 4.9t²
t² = 20/4.9
t² = 4.082
Taking the square root of both sides, we have;
t = 2.02 secs
Therefore, it would take the bullet 2.02 seconds to hit the ground.
1. Which elements would likely have similar properties: two elements in the same group, or two elements in the same period?
2. Fill in the table below with the correct classification of element.
Left side:
Right side:
Zigzag line:
3. Use the periodic table to answer this question: Are the properties of rubidium (Rb) more like those of cesium (Cs) or those of strontium (Sr)? Explain your answer.
4. Use the periodic table at the bottom of the page to identify the elements in the following compounds:
PBS:
KBr:
Rao:
5. Use the periodic table to determine whether each element is a metal or a nonmetal:
Sodium (Na):
Krypton (Kr):
Phosphorus (P):
Answer:
3. Cs, they are in the same group, mainly sharing characteristics.
Explanation:
The elements in the same group have similar properties. The properties of rubidium is similar to those of strontium because, both are in second group.
What are groups in periodic table ?In periodic table, all elements are classified into different periods and groups. The vertical columns in the table is called groups and the horizontal rows are called periods.
The elements in a group have same number of valence electrons and similar chemical and physical properties. For example rubidium and strontium are second group elements and they show similarity in properties.
The elements in the compound, PbS are lead and sulphur and that in KBr are potassium and bromine. Elements in RaO are radium and oxygen. Among the given elements sodium is a metal and krypton and phosphorus are non metals or gases.
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Space-shuttle astronauts experience accelerations of about 35 m/s2 during takeoff. What force does a 75 kg astronaut experience during an acceleration of this magnitude?
Answer:
The answer is 2625 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 75 × 35
We have the final answer as
2625 NHope this helps you
Salmon often jump waterfalls to reach their breeding grounds. Starting downstream, 3.04 m away from a waterfall 0.585 m in height, at what minimum speed must a salmon jumping at an angle of 41.7 ◦ leave the water to continue upstream? The acceleration due to gravity is 9.81 m/s 2 . Answer in units of m/s.
Answer:
V₀ = 5.47 m/s
Explanation:
The jumping motion of the Salmon can be modelled as the projectile motion. So, we use the formula for the range of projectile motion here:
R = V₀² Sin 2θ/g
where,
R = Range of Projectile = 3.04 m
θ = Launch Angle = 41.7°
V₀ = Minimum Launch Speed = ?
g = 9.81 m/s²
Therefore,
3.04 m = V₀² [Sin2(41.7°)]/(9.81 m/s²)
V₀² = 3.04 m/(0.10126 s²/m)
V₀ = √30.02 m²/s²
V₀ = 5.47 m/s
Is there more empty space in an atom or
More mass
What velocity must a 1240 kg car have in order to have the same
momentum as a 3660 kg truck traveling at a velocity of 12 m/s to the
west?
Answer:
90
Explanation:
cause
A skydiver jumps from a plane and falls for 5 seconds before reaching his terminal velocity. During this 5 seconds interval, describe his acceleration before reaching terminal velocity?
Answer:
His acceleration during the first five seconds before reaching terminal velocity = (W - D)/m
Explanation:
The terminal velocity is the maximum steady velocity attained by a body falling freely with increasing velocity from rest in a fluid, such as air or water
The net force, F acting on the body falling through the fluid is given as follows;
F = Weight force, W, from gravity - Drag force, D, from the fluid
F = W - D
Given that F = Mass, m × Acceleration, a, we have;
F = m × a
The acceleration, a = F/m = (W - D)/m
His acceleration during the first five seconds before reaching terminal velocity = (W - D)/m.
Two students are discussing gravity. One student says that there is a gravitational attraction between the two
of them. The other student thinks this cannot be true, because he cannot feel any gravitational attraction to
the other student. Which student is correct, and why?
The student says that there is a gravitational attraction between the two of them. This student is correct.
What is gravitational force?The force of attraction between any two bodies is directly proportional to the product of their masses and is inversely proportional to the square of the distance between them, according to Newton's universal law of gravitation.
The gravitational force is weak unless there are massive masses involved. As compared to Earth, humans have relatively low masses, which results in a very small and negligible gravitational force. As a result, although it is tiny and imperceptible, gravitational force exists between two people seated near to one another.
Hence, the student, who says that there is a gravitational attraction between the two of them, is correct.
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Explain the difference between mass and weight for objects on earth and on the moon
Answer: Gravity causes a change in the mass of objects on earth and the moon.
Explanation:
Because of gravity, the weight of objects lessen, and decrease because of gravity. If you were to drop an object from earth from space, the object would have more mass. Hope that helps.
A train is travelling at 15 m/s. It accelerates at 3 m/s² for 20 seconds. How far does the train travel in this time?
The distance traveled by the train is 900 m.
The given parameters:
Initial velocity of the train, u = 15 m/sAcceleration of the train, a = 3 m/s²Time of motion, t = 20 sWhat is distance?Distance is a scalar quantity that shows the total path covered by an object.The distance traveled by the train is calculated as follows;
[tex]s = ut + \frac{1}{2} at^2\\\\s = (15 \times 20) + (0.5 \times 3 \times 20^2)\\\\s = 900 \ m[/tex]
Thus, the distance traveled by the train is 900 m.
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Answer:
900m
Explanation:
Use the equation: acceleration (a) = change in velocity (v – u) / time taken (t)
Rearrange to solve for the final velocity (v):
v = u + at
Substitute in values and solve:
v = 15 m/s + 3 m/s2 × 20 s = 75 m/s
Rearrange the equation for uniform acceleration (v2 – u2 = 2as) to solve for distance (s):
s = (v2 – u2) / 2a
s = ((75 m/s)2 – (15 m/s)2) / (2 × 3 m/s2)
s = (5,625 m2/s2 – 225 m2/s2) / 6 m/s2
s = 5400 m2/s2 / 6 m/s2
s = 900 m
Light travels in a transparent material at 2.5 x 10 m/s. Find the index of refraction of the
material.
We have that for the Question "Light travels in a transparent material at 2.5 x 10 m/s. Find the index of refraction of the material." it can be said that
From the question we are told
Light travels in a transparent material at 2.5 x 10 m/s. Find the index of refraction of the material.
Generally the equation for the index of refraction is mathematically given as
[tex]n=\frac{C}{v}\\\\Therefore\\\\n=\frac{3*10^8}{2.5 * 10 }\\\\n=12000000\\\\[/tex]
Therefore
The index of refraction of the material is
n=12000000
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A high-speed train in Japan travels a distance of 300. kilometers in 3.60 x 103 seconds. What is the average speed of this train? (Turn the time into hours by using a unit conversion)
Answer:
The average speed is 83.3 m/s
Explanation:
in the movie "gravity" - Why did the escape pod get stuck and pulled back?
Answer:
because nono gravity
Explanation:
no gravity
What happens to the gravitational force between two objects as the bodies become closer to each other? A. The gravitational force begins to repel the objects. B. The gravitational force increases. C. The gravitational force decreases. D. The gravitational force stays the same.
Answer:
Explanation:
The gravitational force between two objects becomes weaker if the two objects are moved apart and stronger if they are brought closer together; that is, the force depends on the distance between the objects.
The gravitational force between two objects as the bodies become closer to each other increases.
Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,
F ∝ m₁.m₂
F ∝ 1/r²
F = G m₁,m₂÷r²
where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².
Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].
As distance decreases the Force increases
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What is thought to make the earth behave as if it contained a huge bar magnet?
Sam stands on a 20 m high cliff and throws a 45 g rock with an initial velocity of 5 m/s [forward] to the water below. Use the conservation of energy to determine the speed of the rock when it has fallen 12 m.
Answer:
v = 12.52 [m/s]
Explanation:
To solve this problem we must use the energy conservation theorem. Which tells us that potential energy is transformed into kinetic energy or vice versa. This is more clearly as the potential energy decreases the kinetic energy increases.
Ep = Ek
where:
Ep = potential energy [J] (units of joules]
Ek = kinetic energy [J]
Ep = m*g*h
where:
m = mass of the rock = 45 [g] = 0.045 [kg]
g = gravity acceleration = 9.81 [m/s²]
h = elevation = (20 - 12) = 8 [m]
Ek = 0.5*m*v²
where:
v = velocity [m/s]
The reference level of potential energy is taken as the ground level, at this level the potential energy is zero, i.e. all potential energy has been transformed into kinetic energy. In such a way that when the Rock has fallen 12 [m] it is located 8 [m] from the ground level.
m*g*h = 0.5*m*v²
v² = (g*h)/0.5
v = √(9.81*8)/0.5
v = 12.52 [m/s]
What role does a resistor play in an electrical circuit
Answer: It opposes the flow of electrons.
Explanation: just did the quiz on
Answer:
It transforms the electrical energy of the electrons into other forms of energy
Explanation:
did quiz
You are taking an image of a patient who is in extreme discomfort while participating in the CT scanning process. Which of the following qualities must you exhibit to obtain a clear and accurate image? O communication skills O interpersonal skills o detail oriented physical endurance
Answer:
Interpersonal skills
Explanation:
Answer:
The right answer is interpersonal skills
Explanation:
give the other person brainliest they deserve it
Annie has 100 mL of honey. The honey has a mass of 145 g. What is the density of the honey?
Answer:
The answer is 1.45 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{145}{100} \\ [/tex]
We have the final answer as
1.45 g/mLHope this helps you
When the energy of a wave increases, what happens to the amplitude?
Answer:
The energy transported by a wave is directly proportional to the square of the amplitude. So whatever change occurs in the amplitude, the square of that effect impacts the energy. This means that a doubling of the amplitude results in a quadrupling of the energy.
Explanation:
When the energy of a wave increases, the amplitude also increases. This is because the amplitude of the wave is directly proportional to the energy of a wave.
What is the amplitude of a wave?The amplitude of a wave may be defined as the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. It is equal to one-half the length of the vibration path.
It is the principle of physics that when the amplitude of the wave is higher, the energy also gets higher. To summarise, waves carry energy. The amount of energy they carry is related to their frequency and their amplitude. The higher the frequency, the more energy, and the higher the amplitude, the more energy.
Therefore, when the energy of a wave increases, the amplitude also increases. This is because the amplitude of the wave is directly proportional to the energy of a wave.
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What is your hypothesis (or hypotheses) for this experiment? (Lab was on Newton’s first two laws of motion)
An unknown substance from planet X has a density of 10 g/mL. It occupies a volume of 80 mL. What is the mass of this unknown substance?
Answer:
800 mL
Explanation:
D*V=M
You pick out the numbers as well as what it is they represent from the word problem/explanation, then from there plug them in to the equations. Once you do that, you get your product and have the answer.
10*80= 800
Name three examples of vortices.
don't lie or else ill report
Answer:
The solutions found include vortex rings, bounded vortices attached to the sphere and infinite vortex tubes.
Explanation:
After running, your friend lies down on a tile floor because he says the "coolness" of the tile transfers to his body. Is this statement true or false?
This is true because the coolness of the tile will transfer to his body.
This is false because the warmth of his body will transfer to the cool tiles.
Answer:
oh this is tricky
Explanation:
this is false because the warmth of his body will transfer to the cool tiles
20. Show that an acceleration of 0.67 m/s/s is the result if a force of 1000N is exerted on a 1500 kg
car.
Explanation:
Given parameters:
Mass of the car = 1500kg
Force applied = 1000N
Acceleration = 0.67m/s²
Unknown:
Proof that the acceleration will result from the applied force on the car
Solution:
According to newton's second law of motion,
Force = mass x acceleration
So;
Acceleration = [tex]\frac{Force }{mass}[/tex]
Now insert the parameters and solve;
Acceleration = [tex]\frac{1000}{1500}[/tex] = 0.67m/s²
We have shown that the acceleration is 0.67m/s²
can someone help rn please!! thank you sm!!
NEED HELP IS THERE SOMEONE CAN HELP ME PLS :)
Write an equation of the line in slope-intercept form.
the faster particles move the less kinetic energy they have true or false
Answer:
False
Explanation:
You get more kinetic energy the more the particles and less kinetic energy with less particles
A sample of oxygen gas occupies a volume of 5.0L at 90kPa pressure. What volume will it occupy at 145kPa?
A. 3.10
B. 5.10
C. 7.0
D. 2.5
Answer:
The answer is option AExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
From the question we have
[tex]V_2 = \frac{5 \times 90000}{145000} = \frac{450000}{145000} = \frac{450}{145} \\ = 3.103448...[/tex]
We have the final answer as
3.10 LHope this helps you
Jen had an average speed of 2.5 m/s when hopping on one foot. If she hopped for 5.0 seconds, for what distance was she hopping?
Explanation:
distance
speed =_________
time
distance = speed × time
= 2.5 × 5.0
distance = 12.5 m
